This is one disease that is far more common in pets than it is in humans. While six in 100,000 people suffer from Cushing’s disease, the condition is about 200 times more common in dogs, with one in 1,000 dogs suffering from the condition.
Cushing’s disease is also known as hyperadrenocorticism.
Cushing’s disease is a slowly progressive disease caused by an excess of the hormone, cortisol, in an animal’s body. Cushing’s disease is the most common hormone-related disease seen in dogs but the disease is rare in other pet species.
Cortisol is a normal hormone that is produced by the adrenal gland and this hormone is essential for normal body function but, in some animals, the adrenal gland produces too much cortisol and Cushing’s disease results.
In some cases, Cushing’s disease is caused by external influences – particularly the long-term administration of cortisone-like medication for the treatment of other diseases, especially skin diseases.
|In some cases, Cushing’s disease is caused by external influences – particularly the long-term administration of cortisone-like medication for the treatment of other diseases.|
Where it is not caused by external administration of cortisone, there are two other causes.
Eighty-five percent of affected dogs have pituitary-dependant hyperadrenocorticism. This form is due to over-stimulation of the adrenal gland by another gland called the pituitary gland, which is located just underneath the brain. One of the pituitary gland’s functions is to control the adrenal gland. It does this by sending specific hormones to the adrenal gland and, in some dogs, the cells of the pituitary gland multiply and excrete too much of these hormones, thus, in turn, overstimulating the adrenal gland to produce too much cortisol.
A further fifteen percent of dogs develop the condition from tumour cells in the adrenal gland itself where these cells pump out excessive amounts of cortisol.
By conducting a variety of tests, your veterinarian will be able to determine which of the two forms of the condition is affecting your dog.
Cushing’s disease is seen mostly in middle-age or older dogs. Poodles, Daschunds, Boxers, Boston Terriers and Beagles seem to be more prone to the disease.
An increase in thirst and therefore increased urine output are common with this condition and affected dogs often develop an increased appetite.
Pets with Cushing’s disease don’t cope well with heat and panting is common. It is common for affected pets to develop a pot-belly appearance and they become over-weight and are lethargic.
Changes to the pet’s coat are often seen. Hair loss and baldness commonly occur along the flanks on both sides of the body and the skin becomes thin and often greasy and malodorous. Changes in skin colour can also occur.
Behavioural changes are also seen with Cushing’s disease. Dogs become lethargic, less friendly towards their owners and often affected dogs don’t sleep well.
If your veterinarian suspects your dog has Cushing’s disease, he or she will confirm the diagnosis with a variety of tests including urine and blood analyses.
Various treatments, including surgery, medications and sometimes radiation therapy, are used to control Cushing’s disease.
While surgery is often used for pituitary tumours that cause Cushing’s disease in humans, surgery is not often conducted for this form of the disease in dogs because of the complexity of the operation. Instead, medications are the usual form of treatment but radiation therapy is also employed in some cases.
If the condition is caused by tumours of the adrenal gland, surgery is more likely, although treatment with medication is also common.
You should keep in close and regular contact with your veterinarian during treatment and after your pet has improved. Regular clinic rechecks are essential and you should expect that survey blood tests will be needed regularly. Once your dog is stabilised, if it becomes sick for any reason, don’t delay visiting your veterinarian.
Regularly measuring your dog’s water consumption is useful. Each day give your dog a measured amount of water in its bowl and, when refilling the bowl the next day, measure the amount left so you know how much your dog has consumed.
Generally, water consumption should be less than 60 millilitres of water per kilogram of body weight per day. For instance, a 10 kilogram dog should be drinking less than 600 millilitres of water per day. However, this is only a guideline as the amount will vary depending on your dog’s activity, the environmental temperature and many other factors.
Also keep a log of your pet’s weight and keep an eye on its appetite and general level of activity. Be careful in hot weather as your dog may be less heat tolerant. Ensure that fresh water is available at all times.